Add support for guest customization section: preamble script and vm name

* add name getter on Vapp, so that we can access it within the VM (vi dep-inject)
* add guest_customization_section test
Fix typo bugs, improve code & test readability

* move machines.yaml to spec/data -- was in wrong place
* tidy trailing whitespace; add vim undo files to .gitignore
* Make memory and cpu method names a bit more descriptive
* add pending unit tests for vm.app
* find and extract common parts of  vm unit tests
* fix typo bug with script_path
* minor refactor of integration test for readability
* add another configuration file example, to test default values
Enable command-line usage of vcloud-provision

* accept a configuration file as ARGV[0]
* remove Fog.credential default, since this prevents use of FOG_CREDENTIAL
* rename Vcloud::Provisioner (to Vcloud::Provision)
  - was conflicting with module of same name, and this matches the tool name
improve spec data/example config; actually test CPU count increase
add some useful debugging when calls to vcloud fail
Improve input handling of memory and cpu, with unit tests
Add utility tool for deleting stopped vapps; basic example input files

* noddy script, but useful
* add helper methods in fog_interface to power on/off & shutdown vapps/vms
Preamble minification + useful example script

* provide a dedicated vapp_name var to ERB, so we do not need to use vapp object
* add minifier.py script
* example script based on previously known-good script
Allow for basic idempotency in runs of the YAML input

* Does not yet handle vm reconfiguration
* Will however skip vapps that already exist, which covers many cases.